Cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material and preparation method thereof

Abstract

The invention discloses a cotton derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material and a preparation method thereof, and belongs to the technical field of multifunctional aerogel. According to the aerogel material, cotton is used as a carbon fiber precursor, and zero-dimensional TiO2 particles, one-dimensional (1D) carbon fibers (CF) and two-dimensional MXene are ingeniously combined together to form a composite material with a three-dimensional (3D) porous structure. The cotton-derived carbon fiber / MXene / TiO2 composite aerogel material disclosed by the invention is excellent in wave-absorbing performance, good in broadband absorption effect, good in capacitive performance and reliable in reversibility.

Description

Technical Field

[0001] The present invention relates to a cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material and a preparation method thereof, belonging to the technical field of multifunctional aerogels. Background Art

[0002] With the rapid development of cyber-physical systems and the Internet of Things (IoT), wireless communication technologies and high-power electronic devices have been widely penetrated into people's production and life. However, the resulting electromagnetic interference and electromagnetic radiation pollution problems are becoming increasingly severe. At the same time, energy shortage has become an increasingly prominent challenge globally. Therefore, it is of great significance to develop multifunctional composite materials with both electromagnetic protection and clean energy storage functions. High-performance electromagnetic wave absorption materials have become a research hotspot in the fields of electronic security, military defense, electromagnetic radiation protection, etc., while supercapacitors have received extensive attention in the energy conversion and storage industry due to their higher power density, faster charge and discharge speed, and longer cycle life compared to batteries and fuel cells. Since a large number of electromagnetic wave absorbing materials and capacitor materials have similarities in component selection and structure design, this inspires us to explore more functions of materials.

[0003] Titanium carbide (Ti3C2T x MXene), as a newly emerging two-dimensional (2D) transition metal carbonitride, is regarded as a promising building block for advanced multifunctional materials due to its large specific surface area, two-dimensional layered structure, rich surface groups, excellent electrical conductivity, and responsiveness to external stimuli. The polar functional groups (-OH, -F, and -O) rich on its surface enable MXene nanosheets to assemble into various macroscopic structures through hydrogen bonding while maintaining their inherent properties. However, the high dielectric constant of MXene will lead to impedance mismatch, restricting the improvement of its electromagnetic properties. To overcome this problem, researchers have improved the dielectric properties of MXene by adjusting experimental conditions, optimizing the structure, and introducing multiple components. For example, integrating the semiconductor TiO2 with a moderate dielectric constant into Ti3C2T x can effectively improve its wave absorption performance due to the effective heterojunction formed between the two and the optimized impedance matching.

[0004] Patent CN202411228703.X discloses a lightweight Co@N-PyC / MXene-BC wave-absorbing aerogel and a preparation method thereof. The material coats the dopamine-derived nitrogen-doped pyrolytic carbon layer and cobalt particles on Ti3C2T through an in-situ self-polymerization and carbonization process xOn the substrate, and introducing bacterial cellulose assembly to form, attributed to surface defects and three-dimensional multi-porous structure, the minimum reflection loss is -66.0 dB at a thickness of 3.0 mm, and the effective bandwidth is 3.8 GHz. However, this aerogel material has weak dielectric loss ability, impedance mismatch, and poor wave absorption performance.

[0005] Patent CN201811006681.7 discloses a preparation method of MXene / cellulose composite aerogel, which is characterized in that a series of steps such as chemical etching, cellulose sol-gel, chemical cross-linking and directional freeze-drying are used to prepare a MXene / cellulose composite aerogel with a directional porous structure. It is difficult to mass-produce, has a high cost, and the phase separation of the composite aerogel results in poor mechanical properties and functionality.

[0006] Ying Li et al. mentioned a preparation method of 3D N-doped carbon fiber / MXene / TiO2 nano-aerogel in the article "Micro-macro regulating heterogeneous interface engineering in 3D N-doped carbon fiber / MXene / TiO2 nano-aerogel for boosting electromagnetic wave absorption". The material forms a three-dimensional framework for constructing a porous structure by introducing biomass-based cotton, in-situ generates TiO2, and dopes nitrogen atoms on Ti3C2T x MXene to adjust its dielectric properties, and successfully constructs 3D N-doped carbon fiber / MXene / TiO2 nano-aerogel. However, the material size is limited by the freeze-drying equipment and cannot be industrially applied.

[0007] Yi Li et al. proposed a three-dimensional porous aerogel composite material with both electromagnetic shielding and wave absorption properties using cellulose nanofibers (CNF) as the framework and Ti3C2T x , aerogel and its electromagnetic shielding and wave-absorbing properties". The material is prepared by mixing CNF and Ti3C2T x MXene in different mass ratios (1:2, 1:1, 2:1, 3:1, 4:1), stirring and freeze-drying. The obtained material has a density of only 10 mg / cm x , and the conductivity can reach 66.95 S / m. However, when Ti3C2T 3 , xWhen the content is relatively high, the material is fragile and has poor formability. Its high conductivity leads to a serious mismatch between the impedance of the material and free space, making it difficult to balance the wave absorption performance and shielding performance.

[0008] Currently, the MXene in existing research is prone to stacking, and its high conductivity limits its use as a wave-absorbing material. The MXene-based composite aerogels constructed are restricted by factors such as production process, cost, and output, and cannot be industrially applied. There are few literature reports on the preparation of cotton-derived carbon fiber / MXene / TiO2 (cotton-derived carbon fiber / MXene / TiO2, CF / MXene / TiO2) composite aerogels by a simple process; at the same time, Ti3C2T x When the content is relatively high, the material is fragile and has poor formability. The existing methods have low yields and are difficult to meet the industrial demand. Therefore, the development of a cotton-derived carbon fiber / MXene / TiO2 composite aerogel that is simple to prepare, low-cost, has excellent performance, and can be industrially produced is of great significance for the development of multifunctional aerogels. Summary of the Invention

[0009] The purpose of the present invention is to provide a cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material and its preparation method. This electromagnetic wave-absorbing material has excellent wave absorption performance, good broadband absorption effect, good capacitance performance, and reliable reversibility.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] Cotton-derived carbon fiber / MXene / TiO2 composite aerogel material (CF / MXene / TiO2), the aerogel material uses cotton as the carbon fiber precursor, and combines zero-dimensional TiO2 particles, one-dimensional (1D) carbon fibers (CF), and two-dimensional MXene together skillfully to form a composite material with a three-dimensional (3D) porous structure.

[0012] A preparation method of the above cotton-derived carbon fiber / MXene / TiO2 composite aerogel material, the method includes the following steps:

[0013] Step 1: Obtain the MXene / PAA composite solution by magnetic stirring and ultrasonic dispersion of the MXene solution and polyacrylic acid (PAA) solution; use cotton as the carbon fiber precursor, under vacuum conditions, immerse the cotton in the mixed solution, and then dry the cotton ball impregnated with the mixed solution to obtain the cotton-derived carbon fiber / MXene / TiO2 nanocomposite material by the vacuum impregnation method;

[0014] Step 2: After the operation in Step 1, the cotton-derived carbon fiber / MXene / TiO2 nanocomposite material is carbonized in an inert gas atmosphere. TiO2 derived from Ti3C2T x can be embedded into the material as "skin pores" to obtain a branched and vine-like cotton-derived carbon fiber / MXene / TiO2 multi-level composite material.

[0015] Furthermore, in Step 1, the content of MXene in the MXene / PAA composite solution is 0.1% - 80%.

[0016] Furthermore, in Step 1, the cotton is immersed in the mixed solution by the vacuum impregnation method for 0.1 - 70 h.

[0017] Furthermore, in Step 1, the cotton balls impregnated with the mixed solution are dried in an oven at 30°C - 100°C to obtain the CF / MXene / PAA composite material.

[0018] Furthermore, in Step 2, the obtained CF / MXene / PAA composite material is carbonized at 200°C - 1200°C under the protection of an inert atmosphere (nitrogen, argon or mixed gas) for 0.5 - 8 h, and the heating rate is 0.1 - 10°C / min. TiO2 is partially derived from Ti3C2T x to obtain the cotton-derived carbon fiber / MXene / TiO2 composite aerogel.

[0019] The beneficial effects of the present invention compared with the prior art are as follows:

[0020] (1) In the cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material of the present invention, the carbon fiber presents a fibrous helical structure with a diameter of 10 - 20 microns, which proves that the later carbonization treatment not only maintains the complete and firm form of the carbon skeleton, but also effectively inhibits the self-stacking phenomenon of MXene nanosheets.

[0021] (2) In the cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material of the present invention, the presence of the carbon fiber skeleton constructs a complete conductive network, which has a significant positive impact on the transmission and transfer of electrons. MXene interpenetrates and adheres between the carbon fibers in an irregular lamellar structure, and the two jointly construct an interlaced three-dimensional interconnected network structure. This unique microscopic morphology not only helps electromagnetic waves to be reflected and scattered multiple times inside the material, thereby significantly improving its wave absorption performance; but also the conductive network is beneficial to achieving excellent capacitance performance.

[0022] (3) The cotton-derived carbon fiber / MXene / TiO2 multifunctional composite aerogel material of the present invention. The combination of zero-dimensional TiO2 particles, one-dimensional CF frameworks, and two-dimensional MXene nanosheets constitutes a unique dendritic multi-level structure, generating abundant microheterogeneous interfaces, which can effectively enhance the interfacial polarization and electromagnetic wave absorption performance. Description of the Drawings

[0023] Figure 1 XRD pattern of 5% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 1 of the present invention -

[0024] Figure 2 SEM image of 5% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 1 of the present invention -

[0025] Figure 3 Electromagnetic loss diagram of 5% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 1 of the present invention -

[0026] Figure 4 XRD pattern of 15% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 2 of the present invention -

[0027] Figure 5 Electromagnetic loss diagram of 15% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 2 of the present invention -

[0028] Figure 6 XRD pattern of 1% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 3 of the present invention -

[0029] Figure 7 Electromagnetic loss diagram of 1% of the cotton-derived carbon fiber / MXene / TiO2 prepared in Example 3 of the present invention - Detailed Embodiments

[0030] The technical solutions in the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase. ​​​​​​​

[0031] Example 1

[0032] A preparation method of a cotton-derived carbon fiber / MXene / TiO2 composite aerogel material specifically includes the following steps:

[0033] Step 1: Prepare MXene and PAA solutions. The MXene solution and PAA solution are magnetically stirred and ultrasonically dispersed to obtain a MXene / PAA composite solution with a MXene content of 5%. Using cotton as the carbon fiber precursor, under vacuum conditions, the cotton is immersed in the mixed solution for 48 h, and then the cotton ball soaked with the mixed solution is dried at 60 °C to obtain a carbon fiber-MXene-PAA nanocomposite material by vacuum impregnation method.

[0034] Step 2: After the above operations, a carbon fiber-MXene-polyacrylic acid (CF / MXene / PAA) nanocomposite material is obtained. It is carbonized in a nitrogen atmosphere at 700 °C for 2 h. The TiO2 derived from Ti3C2T x can be embedded in the material as "skin pores" to obtain a branched and vine-like cotton-derived carbon fiber / MXene / TiO2 multi-level composite material.

[0035] Example 2

[0036] A preparation method of a cotton-derived carbon fiber / MXene / TiO2 composite aerogel material specifically includes the following steps:

[0037] Step 1: Prepare MXene and PAA solutions. The MXene solution and PAA solution are magnetically stirred and ultrasonically dispersed to obtain a MXene / PAA composite solution with a MXene content of 15%. Using cotton as the carbon fiber precursor, under vacuum conditions, the cotton is immersed in the mixed solution for 48 h, and then the cotton ball soaked with the mixed solution is dried at 60 °C to obtain a cotton-derived carbon fiber / MXene / TiO2 nanocomposite material.

[0038] Step 2: After the above operations, a CF / MXene / PAA nanocomposite material is obtained. It is carbonized in a nitrogen atmosphere at 700 °C for 2 h. The TiO2 derived from Ti3C2T x can be embedded in the material as "skin pores" to obtain a branched and vine-like CF / MXene / TiO2 multi-level composite material.

[0039] Example 3

[0040] A preparation method of a cotton-derived carbon fiber / MXene / TiO2 composite aerogel material specifically includes the following steps:

[0041] Step 1: Prepare MXene and PAA solutions. The MXene solution and PAA solution are magnetically stirred and ultrasonically dispersed to obtain a MXene / PAA composite solution with a MXene content of 1%. Using cotton as the carbon fiber precursor, under vacuum conditions, the cotton is immersed in the mixed solution for 48 h, and then the cotton balls impregnated with the mixed solution are dried at 60 °C to obtain the CF / MXene / PAA nanocomposite through the vacuum impregnation method.

[0042] Step 2: After the above operations, the CF / MXene / PAA nanocomposite is obtained and carbonized in a nitrogen atmosphere at 700 °C for 2 h. The TiO2 derived from Ti3C2T x can be embedded into the material as "skin pores" to obtain a branched and vine-like CF / MXene / TiO2 multi-level composite material.

[0043] Figure 1 The XRD pattern of 5% CF / MXene / TiO2 prepared in Example 1 of the present invention; from - it can be found that the broad diffraction peak near 20° - 30° corresponds to the amorphous carbon peak. The diffraction peak at 6.44° corresponds to the (002) crystal plane of Ti3C2T Figure 1 MXene. The diffraction peaks located at 25.72°, 38.34°, 48.24°, 53.86°, 55.46°, and 63.34° correspond to the (101), (004), (220), (105), (211), and (204) crystal planes of TiO2 (PDF#73 - 1764) respectively, and the diffraction peak at 27.54° corresponds to the (110) crystal plane of TiO2. x The SEM image of 5% CF / MXene / TiO2 prepared in Example 1 of the present invention can clearly show that the carbon fibers are intertwined with each other, MXene sheets are interspersed between the fibers, and TiO2 particles are attached to the cotton-derived carbon fibers and MXene. The carbon fibers exhibit a fibrous helical structure with a diameter of 10 - 20 microns, proving that the subsequent carbonization treatment not only maintains the complete and firm form of the carbon skeleton but also effectively inhibits the self-stacking phenomenon of MXene nanosheets.

[0044] Figure 2 The electromagnetic loss map of 5% CF / MXene / TiO2 prepared in Example 1 of the present invention. It can be observed from - it that the lowest reflection loss reaches -56.9 dB at 2.73 mm, and the effective bandwidth at 2.25 mm is 7.66 GHz, covering the entire Ku band (12 - 18 GHz).

[0045] Figure 3 The electromagnetic loss map of 5% CF / MXene / TiO2 prepared in Example 1 of the present invention. It can be observed from - it that the lowest reflection loss reaches -56.9 dB at 2.73 mm, and the effective bandwidth at 2.25 mm is 7.66 GHz, covering the entire Ku band (12 - 18 GHz). Figure 3 it that the lowest reflection loss reaches -56.9 dB at 2.73 mm, and the effective bandwidth at 2.25 mm is 7.66 GHz, covering the entire Ku band (12 - 18 GHz).

[0046] Figure 4 CF / MXene / TiO2 prepared in Example 2 of the present invention - XRD pattern of 15%; the broad diffraction peak near 20° - 30° corresponds to the amorphous carbon peak. The diffraction peak at 6.44° corresponds to Ti3C2T x (002) crystal plane of MXene. The diffraction peaks at 25.72°, 38.34°, 48.24°, 53.86°, 55.46°, and 63.34° correspond to the (101), (004), (220), (105), (211), and (204) crystal planes of TiO2 (PDF#73 - 1764) respectively, and the diffraction peak at 27.54° corresponds to the (110) crystal plane of TiO2.

[0047] Figure 5 CF / MXene / TiO2 prepared in Example 2 of the present invention - Electromagnetic loss pattern of 15%; the material exhibits a minimum reflection loss of -32.82 dB at 3.55 mm, and the effective bandwidth is 5.58 GHz at 1.9 mm.

[0048] Figure 6 CF / MXene / TiO2 prepared in Example 3 of the present invention - XRD pattern of 1%; the broad diffraction peak near 20° - 30° corresponds to the amorphous carbon peak. The diffraction peak at 6.44° corresponds to Ti3C2T x (002) crystal plane of MXene. The diffraction peaks at 25.72°, 38.34°, 48.24°, 53.86°, 55.46°, and 63.34° correspond to the (101), (004), (220), (105), (211), and (204) crystal planes of TiO2 (PDF#73 - 1764) respectively, and the diffraction peak at 27.54° corresponds to the (110) crystal plane of TiO2.

[0049] Figure 7 CF / MXene / TiO2 prepared in Example 3 of the present invention - Electromagnetic loss pattern of 1%; the minimum reflection loss is only -1.9 dB, and there is basically no electromagnetic wave absorption performance.

[0050] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A cotton-derived carbon fiber / MXene / TiO2 composite aerogel material, characterized in that: The aerogel material uses cotton as a carbon fiber precursor, and cleverly combines zero-dimensional TiO2 particles, one-dimensional (1D) carbon fibers (CF) and two-dimensional MXene to form a composite material with a three-dimensional (3D) porous structure.

2. A method for preparing the cotton-derived carbon fiber / MXene / TiO2 composite aerogel material according to claim 1, characterized in that: The method comprises the following steps: Step 1: MXene solution and polyacrylic acid (PAA) solution are subjected to magnetic stirring and ultrasonic dispersion to obtain a MXene / PAA composite solution; cotton is used as a carbon fiber precursor, and the cotton is immersed in the mixed solution under vacuum conditions, and then the cotton ball immersed in the mixed solution is dried to obtain a cotton-derived carbon fiber / MXene / TiO2 nanocomposite material by a vacuum impregnation method; Step 2: After step 1, the cotton-derived carbon fiber / MXene / TiO2 nanocomposite was obtained, which was carbonized under an inert gas atmosphere to obtain Ti3C2T x The derived TiO2 can be embedded into the material as "porphyrin holes" to obtain branched and vine-like cotton-derived carbon fiber / MXene / TiO2 multi-layered composite materials.

3. The method for preparing the cotton-derived carbon fiber / MXene / TiO2 composite aerogel material according to claim 2, characterized in that: In step 1, the content of MXene in the MXene / PAA composite solution is 0.1% to 80%.

4. The method for preparing the cotton-derived carbon fiber / MXene / TiO2 composite aerogel material according to claim 2, characterized in that: In step 1, the cotton is immersed in the mixed solution for 0.1 to 70 hours by vacuum impregnation method.

5. The method for preparing the cotton-derived carbon fiber / MXene / TiO2 composite aerogel material according to claim 2, characterized in that: In step 1, the cotton ball soaked in the mixed solution is dried in an oven at 30° C. to 100° C. to obtain a CF / MXene / PAA composite material.

6. The method for preparing the cotton-derived carbon fiber / MXene / TiO2 composite aerogel material according to claim 2, characterized in that: In step 2, the obtained CF / MXene / PAA composite material is carbonized at 200°C to 1200°C under an inert atmosphere (nitrogen, argon or mixed gas) for 0.5 to 8 h at a heating rate of 0.1-10°C / min. x Part of TiO2 was derived to obtain cotton-derived carbon fiber / MXene / TiO2 composite aerogel.

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